PenLayer: Enable blending in stamp()

Author: adazem009

src/penlayer.cpp

@@ -273,6 +273,8 @@ void PenLayer::stamp(IRenderedTarget *target)
     modelMatrix.scale(scaleX / textureScale, aspectRatio * scaleY / textureScale);
     m_glF->glDisable(GL_SCISSOR_TEST);
     m_glF->glDisable(GL_DEPTH_TEST);
+    m_glF->glEnable(GL_BLEND);
+    m_glF->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
     // Create a FBO for the current texture
     m_glF->glBindFramebuffer(GL_FRAMEBUFFER, m_stampFbo);

test/penlayer/penlayer_test.cpp

@@ -30,11 +30,6 @@ class PenLayerTest : public testing::Test
             m_surface.create();
             Q_ASSERT(m_surface.isValid());
             m_context.makeCurrent(&m_surface);
-
-            QOpenGLFunctions glF(&m_context);
-            glF.initializeOpenGLFunctions();
-            glF.glEnable(GL_BLEND);
-            glF.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
         }
 
         void TearDown() override